Numerical simulation of thermal storage using phase-change material

This dissertation investigates the analysis of thermal energy storage system using phase change materials to improve. In this study for three different distances between tubes in heat exchangers, the effect of inner tubes arrangement on melting and solidification behavior of energy storage system is investigated. Then, in order to investigate the effect of adding tubes, a comparison have been done between heat exchangers with the least melting time. The results show that regardless of the number of tubes, their arrangement and the distance between them, the melting time decreases with respect to one tube heat exchanger. By increasing the number of tubes to five, changing the arrangement with the constant distance between tubes, does not affect melting time, however the distance between tubes is still effective. Comparing the heat exchangers with the least melting time with each other, it can be shown that variation in this distance, increases the melting time. Also increasing the tube numbers to more than four, does not affect the melting time any more. Except two tubes heat exchangers, the least solidification time happens in cases with the least melting time. By increasing the number of tubes from two to three, the time increasing is more than other cases in charging and discharging process.